Character motion jump
From what I've seen online the method usually followed by the character is the following:


Add a small cube. Fix its size to be almost from the feet to the knees of the character.Then make the lowest part of the cube to be in the same height with your character's feet.
Add every motion SCAs to that cube. Only add animations to your character. So the cube will decide where you go and the character when to play the walking/jumping animations.
Set the cube's physics to "character" or "dynamic" or what suits you. Gravity will automatically affect it then.
Last don't forget to parent everything to your cube.


Tip: In order to remember which to select first for parenting think this. When a ship goes down, you pick the children first and then the parents. So the last thing you select is a parent. Read that somewhere.

Edit: Forgot about the bones's physics. Set that to no collision if you don't want it to interact with stuff. Also I think that the parent's physics would overwrite the childrens's. So even if bones was dynamic nothing would make them move differently.